<!DOCTYPE html>
<html>

<head>
    <title>Example 02.01 - Basic Scene</title>
    <script src="../lib/three.js"></script>
    <script src="../lib/stats.js"></script>
    <script src="../lib/dat.gui.js"></script>
    <style>
        body {
            /* set margin to 0 and overflow to hidden, to go fullscreen */
            margin: 0;
            overflow: hidden;
        }
    </style>
</head>

<body>

    <div id="Stats-output">
    </div>

    <!-- Div which will hold the Output -->
    <div id="WebGL-output">
    </div>

    <!-- Javascript code that runs our Three.js examples -->
    <script type="text/javascript">
        // once everything is loaded, we run our Three.js stuff.
        function init() {

            var stats = initStats();

            // create a scene, that will hold all our elements such as objects, cameras and lights.
            var scene = new THREE.Scene();

            // create a camera, which defines where we're looking at.
            var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
            scene.add(camera);

            // create a render and set the size
            var renderer = new THREE.WebGLRenderer();

            renderer.setClearColor(new THREE.Color(0xEEEEEE, 1.0));
            renderer.setSize(window.innerWidth, window.innerHeight);
            renderer.shadowMapEnabled = true;

            // create the ground plane
            var planeGeometry = new THREE.PlaneGeometry(60, 40, 1, 1);
            var planeMaterial = new THREE.MeshLambertMaterial({
                color: 0xffffff
            });
            var plane = new THREE.Mesh(planeGeometry, planeMaterial);
            plane.receiveShadow = true;

            // rotate and position the plane
            plane.rotation.x = -0.5 * Math.PI;
            plane.position.x = 0;
            plane.position.y = 0;
            plane.position.z = 0;

            // add the plane to the scene
            scene.add(plane);

            // position and point the camera to the center of the scene
            camera.position.x = -30;
            camera.position.y = 40;
            camera.position.z = 30;
            camera.lookAt(scene.position);

            // add subtle ambient lighting
            var ambientLight = new THREE.AmbientLight(0x0c0c0c);
            scene.add(ambientLight);

            // add spotlight for the shadows
            var spotLight = new THREE.SpotLight(0xffffff);
            spotLight.position.set(-40, 60, -10);
            spotLight.castShadow = true;
            scene.add(spotLight);

            // add the output of the renderer to the html element
            document.getElementById("WebGL-output").appendChild(renderer.domElement);

            // call the render function
            var step = 0;

            var controls = new function () {
                this.rotationSpeed = 0.02;
                this.numberOfObjects = scene.children.length;

                this.removeCube = function () {
                    var allChildren = scene.children;
                    var lastObject = allChildren[allChildren.length - 1];
                    if (lastObject instanceof THREE.Mesh) {
                        scene.remove(lastObject);
                        this.numberOfObjects = scene.children.length;
                    }
                };

                this.addCube = function () {

                    var cubeSize = Math.ceil((Math.random() * 3));
                    var cubeGeometry = new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize);
                    var cubeMaterial = new THREE.MeshLambertMaterial({
                        color: 0x00ff00
                    });
                    var cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
                    cube.castShadow = true;
                    cube.name = "cube-" + scene.children.length;


                    // position the cube randomly in the scene

                    cube.position.x = -30 + Math.round((Math.random() * planeGeometry.parameters.width));
                    cube.position.y = Math.round((Math.random() * 5));
                    cube.position.z = -20 + Math.round((Math.random() * planeGeometry.parameters.height));

                    // add the cube to the scene
                    scene.add(cube);
                    this.numberOfObjects = scene.children.length;
                };

                this.outputObjects = function () {
                    console.log(scene.children);
                }
            };

            var gui = new dat.GUI();
            gui.add(controls, 'rotationSpeed', 0, 0.5);
            gui.add(controls, 'addCube');
            gui.add(controls, 'removeCube');
            gui.add(controls, 'outputObjects');
            gui.add(controls, 'numberOfObjects').listen();

            render();

            function render() {
                stats.update();

                // rotate the cubes around its axes
                scene.traverse(function (e) {
                    if (e instanceof THREE.Mesh && e != plane) {

                        e.rotation.x += controls.rotationSpeed;
                        e.rotation.y += controls.rotationSpeed;
                        e.rotation.z += controls.rotationSpeed;
                    }
                });

                // render using requestAnimationFrame
                requestAnimationFrame(render);
                renderer.render(scene, camera);
            }

            function initStats() {

                var stats = new Stats();

                stats.setMode(0); // 0: fps, 1: ms

                // Align top-left
                stats.domElement.style.position = 'absolute';
                stats.domElement.style.left = '0px';
                stats.domElement.style.top = '0px';

                document.getElementById("Stats-output").appendChild(stats.domElement);

                return stats;
            }
        }
        window.onload = init
    </script>
</body>

</html>